A model was derived and tested that predicted the spectral reflectance factor from digital data for a dye diffusion thermal transfer printer. The model was based on the Kubelka-Munk turbid media theory and included terms to account for back diffusion onto
the donor supply and dye transfer inhibition. The average colorimetric characterization accuracy of the printer's color gamut based on 45 samples to estimate the model parameters was 3.0 ΔE*ab with a maximum of 7.4. The spectral model had similar performance to look-up table and multidimensional interpolation methods and superior performance to multiple-linear regression methods based on tristimulus data.